Urge and mixed urinary incontinence are common conditions, affecting 10-20% of American women. While several treatment modalities exist, pharmacotherapy remains the mainstay of treatment. Much of the research pertaining to treatment for urge and mixed incontinence is limited by short duration of follow-up, homogeneous patient populations, stringent exclusion criteria, poorly defined outcome measures, and lack of placebo control. Factors that predict success or failure of specific treatments are poorly understood. The broad objectives of this prospective randomized clinical trial are to describe and compare the efficacy (Phase 1) and the longer term effectiveness (Phase 2) of several treatments for urge and mixed incontinence, to determine the predictive value of pre-treatment urodynamics, and to understand factors associated with treatment efficacy and effectiveness. 400 women with urge incontinence or mixed incontinence with urge as the predominant symptom will be randomly assigned to one of four treatment groups: (1) tolterodine, (2) physiotherapy plus placebo, (3) physiotherapy plus tolterodine, and (4) placebo alone. The primary outcome measure used to define treatment efficacy at three months (Phase 1) is at least a 50% reduction from baseline in the number of incontinent episodes per week (of at least 60. Secondary outcomes measures include (1) voiding frequency, (2) patient satisfaction as recorded on a visual analogue scale, (3) adverse events, (4) urge incontinence specific quality of life measure, (5) pelvic floor distress inventory, (6) sexual function assessment tool, and (7) generic quality of life measure. Following evaluation of Phase 1 outcomes, women will continue to be followed every 3 months for 1 year. Women unsuccessfully treated will be offered alternative therapy. Medium term (one year) effectiveness of treatments for urge and mixed incontinence will be described by comparing baseline and one-year outcome measures. All data will be analyzed in an intent-to-treat fashion. The specific aims of this study are 1) to describe and compare the 3- month and 1-year efficacy of urge incontinence treatment among the 4 groups stated above, 2) to determine whether specific pre-treatment urodynamic variables are predictive of treatment efficacy, 3) to identify factors associated with treatment efficacy, and 4) to describe the difference in clinical course and quality of life among treatment groups and as compared to baseline after 3 months and 1 year of intervention.